(a) Field of the Invention
The present invention relates to a bicycle having a wheel height adjustment structure for improvement of safety in riding up or down a slope by adjusting the height of a rear wheel according to the intention of a bicycle rider.
(b) Description of the Related Art
In general, a bicycle frame is formed of a head tube, a sheet tube, a top tube, a down tube, a sheet stay, and a chain stay.
The head tube is connected with a connection body of a steering handle through an upper end of the head tube and a front wheel rotation connection body through a bottom end of the head tube, and the sheet tube is connected with a saddle connection body through an upper end of the sheet tube and a chain driving body through a bottom end of the sheet tube.
The top tube and the down tube support the head tube and the sheet tube by connecting the head tube and the sheet tube, and the sheet stay and the chain stay support a rear wheel rotation connection body and the sheet tube by connecting the rear wheel rotation connection body and the sheet tube.
The bicycle frame is usually equipped with the top tube and the down tube, but a main tube (not shown) may be connected between the head tube and the sheet tube as necessary.
A typical bicycle frame is formed by respectively cutting a tube into a top tube, a down tube, and a sheet tube and welding the respective tubes. However, the manufacturing process cannot be automated, thereby deteriorating productivity and causing an increase of manufacturing cost.
Recently, a process for manufacturing a bicycle frame by stamping a panel and bonding the stamped panel at the left and right thereof has been researched and developed to thereby improve production efficiency and durability.
When a bicycle rider brakes the bicycle, the center of gravity of the bicycle moves forward so that a rollover accident may occur, and when the rider is riding the bicycle on an uphill road, the center of gravity of the bicycle moves rearward and thus a front wheel is lifted from the ground, thereby reducing a grip force of the wheel.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.